Descripción de componentes de la arquitectura SOA

Based on the user tasks defined on the top, look at the chart type and data type they represent to form an initial idea on which chart to use. This is not an exauhstive list but a starting point in using 3D visualization.

Readability

Readability of the graph is decided on the basis of Cleveland et al.[63]

study of graphical perception, occlusion of graphical elements, and novelty of layout. Readability of the visualization is also affected by the task that needs to performed, the design (i.e. the colors and layout) of the visualization, and the dataset to be visualized.

Force Directed Graph

Shows the strength and inter-connect- edness of relationships. Can be used to show flow using animation.

3D Stacked Bar Chart

Shows the magnitude across 2 categorical variables

3D Bar Chart

Shows the magnitude across 2 categorical variables

Shows the magnitude across 2 categorical variables

3D Bar Chart

Compares magnitude across 2 categorical variables

3D Scatter Plot

Shows relationship between 3 continuous numeric variables

3D Contour Plot

Shows the relationship of functions x=f(y) and z=g(y)

3D Bar Chart

Shows the distribution across 2 categorical variables (in the form of a 3D histogram)

Prism Map

Shows the magnitude of a variable spatially

3D Time Series

Shows change over time for 2 continuous variables

64 Interactivity

subset of the data or examine the data from a different point of view[64]_{. Since VR is an immerssive medium, user can the walk} towards or away from the visualization and also move around the visualization, thus allowing the users to explore and focus on point of interest. This can be seen as a literal implementation of the direct-walk technique which is explained by Card et al.[64] _as “a task in which a user navigates from a starting point to a goal

point in an information structure by a series of mouse points or other direct manipulation methods”.

The ability to rotate the camera using the HMD allows the user to see the visualization from different point of views, for example top view or side views. This not only allows the user to focus on subset of data but also helps the user gain insights about the data by showing the data from different point of view.

Select/Focus

Select interaction techniques provide users with the ability to select or focus on a data item of interest and find details about that item. VR-Viz uses mouse over effect as key select interaction technique. This interaction is straight forward but there are some issues when designing mouse over effect for VR. In VR there are multiple ways to place and visualize the UI elements:

• Spatial UI: UI is placed within the 3D scene. This method

over as the UI might be placed in a position which is not in the FOV of the user.

• UI attached to the body: There are two option for this

method: UI attached to head (HMD) and UI attached to hand (controllers). VR-Viz uses UI attached to hand for mouse over effect as UI attached to head can cause occlusion and hide the visualization in front.

In VR-Viz the information that appear on mouse over is attached to one of the controllers so that the effect can be view easily all the time no matter the position or viewing angle of the user in the scene. The information must not be placed very close to the camera as it can cause strain to the user.

3.7 FUTURE DEVELOPMENT

Development of VR-Viz is a continuous process. In the present state, VR-Viz contains 24 visualization techniques and basic interactivity features.

In future, more visualization techniques will be added: like 3D lollipop chart, 3D bump chart, exploded view drawing and map visualizations on a spherical earth.

Currently, the interactivity feature is very basic, and need further developement. Interactivity features that will be added in future releases are the ability of user to rotate and scale

66 Summary

the visualization and move around the visualization using teleportation. Another key feature that is missing is the ability to show legend and title of the visualization, which will also be added in future releases.

Animations are used in information visualization to convey changes over time, transitions, or for storytelling. Vr-Viz is lacking this feature and it’s development is in the pipelines.

3.8 SUMMARY

This chapter provides an overview of VR-Viz. VR-Viz is developed as an easy to use, accesible, and efficient visualization tool for designing and developing information visualization in VR. VR-Viz is an open source system available at https://github.

com/mustafasaifee42/vr-viz. By offering an easy to use tool

for information visualization in VR, VR-Viz facilitates rapid exploration and prototyping of VR information visualizations. VR-Viz provides an oppurtunity for the researchers to create rapid prototypes of VR visualization, and further the research in this field. Ultimately, we hope that it enables developers, designers, and analysts to produce more VR information visualization with the same ease with which they currently design web visualization.

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